Select the correct statement about membrane permeability and ion potential.
A) the concentration of potassium ions is the same extracellularly and intracellularly.
B) the concentration of potassium is higher extracellularly than intracellularly.
C) the concentration of sodium is higher extracellularly than intracellularly.
D) the membrane is more permeable to anions than to potassium.
E) the membrane is more permeable to sodium than to potassium.

Question

Quizplus · Accepted Answer

The statement "the concentration of sodium is higher extracellularly than intracellularly" is correct. This is due to the action of the sodium-potassium pump, which pumps sodium out of the cell and potassium into the cell, creating a concentration gradient that favors the movement of sodium into the cell and potassium out of the cell. The other statements are incorrect: A is incorrect because the concentration of potassium is higher intracellularly than extracellularly; B is incorrect because the concentration of potassium is higher intracellularly than extracellularly; D is incorrect because anions are negatively charged and are not as easily able to cross the cell membrane as positively charged ions like potassium; and E is incorrect because the membrane is actually more permeable to potassium than to sodium.

Select the Correct Statement About Membrane Permeability and Ion Potential